Ejnar Hertzsprung

Click HERE for Q. No.1-50.

51) Planets are always small compared with stars because otherwise ______.
( a) the rotation of the planets would cause them to disintegrate
(b) the great mass of the planets would cause them to be pulled into their parent star
(c) the great mass of the planets would prevent them from being held in orbit and they would escape
(d) the planets would be stars themselves
Answer: (d)

52) The least likely reason why planetary systems have not been directly observed around stars other than the sun is that __
(a) Planets are small
(b) Planets shine by reflected light
(c) Planetary systems are rare
(d) Other stars are far away
Answer: (c)

53) Which of the following is the correct ordering of the inner planets according to their proximity to the sun? (CSS 2012)
(a) Jupiter, Saturn , Uranus , Neptune
(b) Phobos, Deimes , Europe , Tias
(c) Mercury, Venus, Earth, Mars
(d) None of these
Answer: (c)

54) The term ‘Blue Shift’ is used to indicate: (CSS 2009)
(a) Doppler effect in which an object appears bluer when it is moving towards the observer or observer is moving towards the object.

(b) Turning a star from white to blue
(c) In future sun would become blue
(d) Black hole was blue at its start
(e) None of these
Answer: (a)

55) Which planet of our solar system is called as Morning star? (CSS 2008)
Answer: Venus

56) What is the diameter of the earth?
Answer: 12 756.2 kilometers

57) The number of natural satellites orbiting around the Mars is: (CSS 2002/2003)
(a) 1
(b) 2
(c) 5
(d) 14
Answer: (b)
Mars has two natural satellites, discovered by Asaph Hall in 1877. The innermost of these, Phobos, is about 7 mi (11 km) in diameter and orbits the planet with a period far less than Mars’s period of rotation (7 hr 39 min), causing it to rise in the west and set in the east. The outer satellite, Deimos, is about 4 mi (6 km) in diameter.

58) All stars are of the same color
(False)

59) Our galaxy milky way is shaped like a large thick concave lens with a large central bulge (CSS 2002)
(True)

60) The coldest planet of the solar system is: (CSS 2000)
(a) Earth
(b) Venus
(c) Neptune d) Pluto
(e) None of these
Answer: (c)
In the past, the title for “most frigid body” went to Pluto, as it was the farthest then-designated planet from the Sun. However, due to the IAU’s decision in 2006 to reclassify Pluto as a “dwarf planet”, the title has since passed to Neptune. As the eight planet from our Sun, it is now the outermost planet in the Solar System, and hence the coldest.

61) Venus is the smallest planet of the solar system. (CSS 1999)
(False)

62) Black hole is a hypothetical region of space having a gravitational pull so great that no matter or radiation can escape from it. (CSS 1998)

63) Our solar system has about — satellites. (CSS 1996)
(a) 35
(b) 179
(c) 96
(d) None of these
Answer: (b)
In the Solar System, there are 179 satellites. A majority of those moons belong to the planet of Jupiter, the second most belonging to Saturn. The largest of these moons is Ganymede, which is one of the Galilean Moons.

64) ——- cannot be nominated for the Nobel Prize. (CSS 1996)
(a) Physicists
(b) Economists
(c) Astronomers
(d) None of these
Answer: (c)

65) The largest planet of the solar system is Jupiter. (CSS 1995)

66) Planet Mars has (CSS 1995)
(a) 1 Moon
(b) 2 Moons
(c) 4 Moons
(d) None of these
Answer: (b)
The moons of Mars are Phobos and Deimos. Both moons were discovered in 1877 by Asaph Hall Asaph Hall was about to give up his frustrating search for a Martian moon one August night in 1877, but his wife Angelina urged him on. He discovered Deimos the next night, and Phobos six nights after that. Ninety-four years later, NASA’s Mariner 9 spacecraft got a much better look at the two moons from its orbit around Mars. The dominant feature on Phobos, it found, was a crater 10 km (6 miles) wide — nearly half the width of the moon itself. It was given Angelina’s maiden name: Stickney.

67) Where do most of Asteroids lie? (CSS 2007)
(a) In asteroid belt between the orbits of Mars and Jupiter
(b) In asteroid belt between the orbits of Mars and Venus
(c) In asteroid belt between the orbits of Jupiter and Venus
(d) Everywhere in the sky
(e) None of these
Answer: (a)

68) This is the measure of moisture in the air.
(a) Temperature
(b) Humidity
(c) Altitude
(d) None of these
Answer: (b)

69) This is the greatest amount of water vapor the air could hold at a certain temperature
(a) Absolute humidity
(b) Relative humidity
(c) Variable humidity
(d) None of these
Answer: (a)
Absolute humidity is the measure of water vapor (moisture) in the air, regardless of temperature. It is expressed as grams of moisture per cubic meter of air (g/m3).
The maximum absolute humidity of warm air at 30°C/86°F is approximately 30g of water vapor – 30g/m3. The maximum absolute humidity of cold air at 0°C/32°F is approximately 5g of water vapor – 5g/m3.

70) This is how much actual water vapor is in the air at a certain temperature.
(a)Absolute humidity
(b) Relative humidity
(c) Variable
(d) None of these
Answer: (b)
Relative humidity also measures water vapor but RELATIVE to the temperature of the air. It is expressed as the amount of water vapor in the air as a percentage of the total amount that could be held at its current temperature.

71) Humidity is measured with a
(a) Barometer
(b) Thermometer
(c) Hygrometer
(d) None of these
Answer: (c)

72) Founder of modern astronomy was: (CSS-2009)
(a) Archimedes
(b) William Gilbert
(c) Nicolas Copernicus
(d) Michael Faraday
(e) None of these
Answer: (c)

73) The most splendid and the most magnificent constellation on the sky is: (CSS-2009)
(a) Orion
(b) Columbia
(c) Canis Major
(d) Taurus
(e) None of these
Answer: (a)
(Canis Major is a constellation in the southern sky. Its name means “the greater dog” in Latin.) Orion, which is located on the celestial equator, is one of the most prominent and recognizable constellations in the sky and can be seen throughout the world.

74) Which of the following explains the reason why there is no total eclipse of the sun? (CSS-2009)
(a) Size of the earth in relation to that of moon
(b) Orbit of moon around earth
(c) Direction of rotation of earth around sun
(d) Area of the sun covered by the moon
(e) None of these
Answer: (b)

75) Where do most of Asteroids lie? (CSS-2009)
(a) In asteroid belt between the orbits of Mars and Jupiter
(b) In asteroid belt between the orbits of Mars and Venus
(c) In asteroid belt between the orbits of Jupiter and Venus
(d) Everywhere in the sky
(e) None of these
Answer: (a)
Most asteroids lie in a vast ring between the orbits of Mars and Jupiter. This main asteroid belt holds more than 200 asteroids larger than 60 miles (100 kilometers) in diameter. Scientists estimate the asteroid belt also contains more than 750,000 asteroids larger than three-fifths of a mile (1 km) in diameter and millions of smaller ones. Not everything in the main belt is an asteroid — for instance, comets have recently been discovered there, and Ceres, once thought of only as an asteroid, is now also considered a dwarf planet.

76) The largest circular storm in our solar system is on the surface of which of the following planets?
(a) Jupiter
(b) Venus
(c) Uranus
(d) Earth
Answer: (a)
Jupiter boasts the largest storm in the Solar System . It is called the Great Red Spot and has been observed for hundreds of years that kind of storm is dwarfed by the Great Red Spot, a gigantic storm in Jupiter. There, gigantic means twice as wide as Earth. Today, scientists know the Great Red Spot is there and it’s been there for a while, but they still struggle to learn what causes its swirl of reddish hues.

77) The biggest asteroid known is:
(a) Vesta
(b) Icarus
(c) Ceres
(d) Eros
Answer: (c)
Ceres, a dwarf planet and the largest asteroid in the solar system yet known. Discovered in 1801 and first thought to be a planet and then an asteroid, we now call Ceres a dwarf planet. Gravitational forces from Jupiter billions of years ago prevented it from becoming a full-fledged planet. But Ceres has more in common with Earth and Mars than its rocky neighbors in the main asteroid belt. There may even be water ice buried under Ceres’ crust.

78) Rounded to the nearest day, the Mercurian year is equal to:
(a) 111 days
(b) 87.97 days
(c) 50 days
(d) 25 days
Answer: (b)
Mercurian Year: A year on Mercury takes 87.97 Earth days; it takes 87.97 Earth days for Mercury to orbit the sun once

79) One of the largest volcanoes in our solar system-if not the largest-is named Olympus Mons. This volcano is located on:
(a) Jupiter’s moon Callisto
(b) Venus
(c) Saturn’s moon Titan
(d) Mars
Answer: (d)
Olympus Mons is the largest volcano in the solar system. The massive Martian mountain towers high above the surrounding plains of the red planet, and may be biding its time until the next eruption. Olympus Mons rises three times higher than Earth’s highest mountain, Mount Everest, whose peak is 5.5 miles above sea level.

80) One Jupiter day is equal to which of the following?
(a) 30 hrs 40 min
(b) 9 hrs 50 min
(c) 3 hrs 20 min
(d) 52 hrs 10 min
Answer: (b)

81) The time interval between two successive occurrences of a specific type of alignment of a planet (or the moon) with the sun and the earth is referred to as:
(a) a conjunction
(b) an opposition
(c) a sidereal period
(d) a synodic period.
Answer: (d)
Synodic period , in astronomy, length of time during which a body in the solar system makes one orbit of the sun relative to the earth, i.e. The synodic period of the moon, which is called the lunar month, or lunation, is 291/2 days long; it is longer than the sidereal month.

82) Of the following four times, which one best represents the time it takes energy generated in the core of the sun to reach the surface of the sun and be radiated?
(a) Three minutes
(b) Thirty days
(c) One thousand years
(d) One million years
Answer: (d)

83) The sunspot cycle is:
(a) 3 years
(b) 11 years
(c) 26 years
(d) 49 years
Answer: (b)

The amount of magnetic flux that rises up to the Sun’s surface varies with time in a cycle called the solar cycle. This cycle lasts 11 years on average. This cycle is sometimes referred to as the sunspot cycle.

84) The Hertzsprung-Russel Diagram of stars DIRECTLY compares what TWO of the following properties of stars?
(a) size
(b) temperature
(c) luminosity
(d) Both b & c
Answer: (d)
One of the most useful and powerful plots in astrophysics is the Hertzsprung-Russell diagram (hereafter called the H-R diagram). It originated in 1911 when the Danish astronomer, Ejnar Hertzsprung, plotted the absolute magnitude of stars against their color (hence effective temperature). Independently in 1913 the American astronomer Henry Norris Russell used spectral class against absolute magnitude. Their resultant plots showed that the relationship between temperature and luminosity of a star was not random but instead appeared to fall into distinct groups.

The majority of stars, including our Sun, are found along a region called the Main Sequence. Main Sequence stars vary widely in effective temperature but the hotter they are, the more luminous they are, hence the main sequence tends to follow a band going from the bottom right of the diagram to the top left. These stars are fusing hydrogen to helium in their cores. Stars spend the bulk of their existence as main sequence stars. Other major groups of stars found on the H-R diagram are the giants and supergiants; luminous stars that have evolved off the main sequence, and the white dwarfs. Whilst each of these types is discussed in detail in later pages we can use their positions on the H-R diagram to infer some of their properties.

85) The Andromeda Galaxy is which of the following types of galaxies?
(a) elliptical
(b) spiral
(c) barred-spiral
(d) irregular
Answer: (b)
The Andromeda Galaxy also known as Messier 31, M31, or NGC 224, is a spiral galaxy approximately 780 kilo parsecs (2.5 million light-years) from Earth

86) About how many light years across is the Milky Way? Is it:
(a) 1,000
(b) 10,000
(c) 100,000
(d) 1,000,000
Answer: (c)
100 000 light years across
A light-year is precisely equal to a whole number of meters, namely 9460730472580800 m or approximately 9.46073 1015 m. That’s the distance traveled by light in a vacuum, at a speed of 299792458 m/s, during a “scientific year” of 31557600 s. All these numbers are exact… In particular, “Einstein’s Constant” is exactly c = 299792458 m/s, because of the latest definition of the meter, officially adopted in 1983.

87) Who was the first man to classify stars according to their brightness. Was it:
(a) Aristarchus
(b) Pythagoras
(c) Copernicus
(d) Hipparchus
Answer: (d)
The first person to classify stars by their apparent magnitude (brightness) was Hipparchus in about 130 BC. He divided the stars into classes based on how bright they appeared in the night sky. The brightest stars were classified as magnitude 1, those that were just visible to the naked eye as magnitude 6. In practice the intensity of a magnitude 1 star is 100 times that of a magnitude 6 star, so the 5 magnitude steps correspond to a multiple of 100. For a geometric series of magnitudes each magnitude must be a times the intensity of the previous one with a5 – 100. This means that going up one magnitude increases the intensity by a factor of a = 2.51. So magnitude 3 is 2.51 times as intense as magnitude 4 and so on.

88) For what reason was the Schmidt telescope specially built? Was it to serve as:
(a) a sky camera
(b) a radio telescope
(c) an optical telescope
(d) a solar telescope
Answer: (a)

A Schmidt camera, also referred to as the Schmidt telescope, is a catadioptric astrophotographic telescope designed to provide wide fields of view with limited aberrations. The design was invented by Bernhard Schmidt in 1930.

89) The greatest distance of a planet from the sun is called what? Is it the planet’s:
(a) aphelion
(b) perihelion
(c) helix
(d) eccentricity
Answer: (a)
The closest point to the Sun in a planet’s orbit is called perihelion. The furthest point is called aphelion

90) How is the atmospheric pressure of Mars as compared to the atmospheric pressure of the earth? Is it:
(a) about the same as the earth’s
(b) about 100 times as great as the earth’s
(c) about 1/200th that of the earth’s
(d) half as much as that of the earth’s
Answer: (c)
The atmosphere and (probably) the interior of Mars differ substantially from that of the Earth. The atmosphere is much less dense and of different composition, and it is unlikely that the core is molten.
The atmosphere has a pressure at the surface that is only 1/200 that of Earth. The primary component of the atmosphere is carbon dioxide (95%), with the remainder mostly nitrogen. Seasonal heating drives strong winds that can reach 100 mph or more, stirring up large dust storms. Clouds form in the atmosphere, but liquid water cannot exist at the ambient pressure and temperature of the Martian surface: water goes directly between solid and vapor phases without becoming liquid.

91) A typical galaxy, such as our Milky Way galaxy, contains how many billion stars? Is it approximately:
(a) 10 billion
(b) 40 billion
(c) 400 billion
(d) 800 billion
Answer: (c)
According to astronomers, our Milky Way is an average-sized barred spiral galaxy measuring up to 120,000 light-years across. Our Sun is located about 27,000 light-years from the galactic core in the Orion arm. Astronomers estimate that the Milky Way contains up to 400 billion stars of various sizes and brightness.
According to astronomers, there are probably more than 170 billion galaxies in the observable Universe, stretching out into a region of space 13.8 billion light-years away from us in all directions.

92) A comet’s tail points in which direction?
(a) toward the sun
(b) toward the earth
(c) behind the comet in its orbit
(d) away from the sun
Answer: (d)
Comet tails are expansions of the coma. Comet tails point away from the Sun, regardless of the direction in which the comet is traveling. Comets have two tails because escaping gas and dust are influenced by the Sun in slightly different ways, and the tails point in slightly different directions.

93) Spectral line splitting due to the influence of magnetic fields is called:
(a) Boltzmann Effect
(b) Zeeman Effect
(c) Planck Effect
(d) Zanstra’s Effect
Answer: (b)
The Zeeman effect is the splitting of a spectral line by a magnetic field. That is, if an atomic spectral line of 400 nm was considered under normal conditions, in a strong magnetic field, because of the Zeeman effect, the spectral line would be split to yield a more energetic line and a less energetic line, in addition to the original line at 400 nm.

94) Which of the following is true for ORION? Orion is:
(a) the brightest star in the sky
(b) a constellation
(c) the name given to a NASA spacecraft
(d) an asteroid
Answer: (b)

95) Which of the following men wrote the book “On the Revolutions of the Heavenly Spheres”?
(a) Kepler
(b) Euclid
(c) Copernicus
(d) Newton
Answer: (c)

De revolutionibus orbium coelestium (On the Revolutions of the Heavenly Spheres) is the seminal work on the heliocentric theory of the Renaissance astronomer Nicolaus Copernicus (1473–1543).

96) The most distant planet in the solar system is (CSS 1995)
(a) Mars
(b) Pluto
(c) Jupiter
(d) None of these
Answer: (d)
New Dwarf Planet In Our Solar System May Be The Farthest One Yet. Object V774104 was discovered in late October, 2015, and is one of the most distant objects ever detected in the solar system. It appears to be about half the size of Pluto, but with an orbit two to three times larger than Pluto’s. (Nov 12, 2015)

97) The 2.7 Kelvin cosmic background radiation is concentrated in the:
(a) radio wavelengths
(b) infrared
(c) visible
(d) ultraviolet
Answer: (a)

98) If you were watching a star collapsing to form a black hole, the light would disappear because it:
(a) is strongly red shifted
(b) is strongly blue shifted
(c) its color suddenly becomes black
(d) none of the above
Answer: (a)

99) The Magellanic Clouds are
(a) irregular galaxies
(b) spiral galaxies
(c) elliptical galaxies
(d) large clouds of gas and dust
Answer: (a)
The Magellanic Clouds are comprised of two irregular galaxies, the Large Magellanic Cloud (LMC) and the Small Magellanic Cloud (SMC), which orbit the Milky Way once every 1,500 million years and each other once every 900 million years. Lying only about 200,000 light years away, they were the closest known galaxies to the Milky Way until recently, when the Sagittarius and Canis Major dwarf galaxies were discovered and found to be even closer.

100) According to Kepler’s Laws, the cube of the mean distance of a planet from the sun is proportional to the:
(a) area that is swept out
(b) cube of the period
(c) square of the period
(d) fourth power of the mean distance
Answer: (c)